Induction device

ABSTRACT

An induction device includes an induction unit including a sensor unit which is arranged above the induction unit in a mounted position and includes a plurality of temperature sensor elements arranged in a distributed manner and configured to detect a sensor parameter in the form of a temperature parameter of a unit. A control unit is provided to analyze the sensor parameter.

The invention relates to an induction device according to the preambleof claim 1.

An induction device with a plurality of induction units arranged in themanner of a matrix and with a sensor unit for detecting a sensorparameter, which is in the form of a temperature parameter of at leastone unit and in particular of at least one placement plate, is alreadyknown from the prior art. The sensor unit has one temperature sensorelement per induction unit, which is arranged on the induction unit andis configured as a thermistor or RTD (resistance temperature detector).

It is the object of the invention in particular to provide a genericdevice with improved properties in respect of a detection of particularparameters. According to the invention the object is achieved by thefeatures of claim 1, while advantageous embodiments and developments ofthe invention will emerge from the subclaims.

The invention is based on an induction device, in particular aninduction cooktop device, with at least one induction unit, inparticular with at least one induction heating unit, with at least onesensor unit, which is provided to detect at least one sensor parameter,and with at least one control unit, which is provided to analyze thesensor parameter.

It is proposed that in a mounted position the sensor unit is arrangedabove the induction unit and has a plurality of presence sensor elementsarranged in a distributed manner, in particular in the manner of amatrix, being provided to detect at least one sensor parameter in theform of a presence parameter of at least one object, in particular of atleast one positioned cookware item, and/or a plurality of activitysensor elements arranged in a distributed manner, in particular in themanner of a matrix, being provided to detect at least one sensorparameter in the form of an activity parameter of the induction unit,and/or a plurality of temperature sensor elements arranged in adistributed manner, in particular in the manner of a matrix, beingprovided to detect at least one sensor parameter in the form of atemperature parameter of at least one unit.

The inventive embodiment in particular allows advantageous detection ofparticular parameters. By arranging the sensor unit above the inductionunit it is possible in particular to achieve a compact configuration. Inparticular it allows precise detection, in particular due to the spatialproximity of the sensor unit to the induction unit and/or a placementplate and/or a cookware item. The modular and/or independent nature ofthe sensor unit relative to the induction unit in particular allowsindependence of the sensor unit and the induction unit, therebypreventing any change to the sensor unit and/or the induction unitaffecting the induction unit and/or the sensor unit.

The presence sensor elements in particular allow precise detection ofpositioned cookware and/or the object, in particular when there is amuch smaller, in particular unwanted, transfer of energy to the objectto be detected, compared with sensor elements formed by the inductionunit. The plurality of presence sensor elements in particular allows ahigh resolution capacity to be achieved, allowing even small objectsand/or cookware items in particular to be detected easily.

The activity sensor elements in particular allow precise detection ofany activity of the induction unit, thereby in particular preventingerroneous activation of an induction unit and/or providing a high safetystandard. In particular by only activating required induction units itis possible to achieve an environmentally friendly and/or economicalembodiment, which is therefore in particular extremely convenient forthe operator. In particular there is no need for an additional circuitfor detecting an electric voltage and/or an electric current of theinduction unit, thereby keeping costs low.

The temperature sensor elements in particular allow precise detection ofa temperature of the unit, allowing optimal cooking results inparticular to be achieved. Overheating of a unit, which could inparticular be the induction unit and/or the placement plate, inparticular can be avoided, resulting in particular in a durableembodiment. In particular an item being cooked is prevented from burningand/or boiling dry, which is in particular convenient for the operator.

An “induction device”, in particular an “induction cooktop device”refers in particular to at least one part, in particular a sub-assembly,of an induction appliance, in particular of an induction cooktop. Theinduction device is preferably provided to transfer energy inductivelyto at least one item. The item could be for example a self-driving workimplement and/or a hand tool and/or a shutter and/or a remote controlunit. The item is preferably a cookware item. In particular the item canbe identical to the object which is provided in particular for detectionusing the plurality of presence sensor elements, in particular if theobject is provided to transfer energy inductively.

The induction device configured in particular as an induction cooktopdevice could have for example at least one placement plate, inparticular configured as a cooktop plate, which could be provided inparticular for cookware placement, in particular for the purpose ofheating the cookware, and, in particular together with at least onehousing unit of the induction device, could define and/or form at leastone outer housing, in particular at least one cooktop outer housing inparticular of at least one induction cooktop comprising the inductiondevice. In particular the induction device, which in particularcomprises the placement plate configured in particular as a cooktopplate, could be provided for delivery and/or sale, in particulartogether with the placement plate configured in particular as a cooktopplate.

Alternatively the induction device configured in particular as aninduction cooktop device could be for example without a placement plateand be provided in particular for arrangement below a placement plateconfigured in particular as a worktop and advantageously as a kitchenworktop. In particular the induction device, which could be inparticular without a placement plate configured in particular as aworktop, could be provided for delivery and/or sale separately from atleast one placement plate configured in particular as a worktop. Theplacement plate configured in particular as a worktop and advantageouslyas a kitchen worktop could be for example part of at least one cookingsystem, which could comprise in particular the induction device and inparticular the placement plate configured in particular as a worktop andadvantageously as a kitchen worktop.

In particular the induction device has at least two, advantageously atleast three, particularly advantageously at least four, preferably atleast eight and particularly preferably a plurality of induction units.The induction units are arranged in particular in a distributed mannerand advantageously in the manner of a matrix. An “induction unit” inthis context refers in particular to a unit, which, in at least oneoperating state, provides energy, in particular in the form of anelectromagnetic alternating field, advantageously for the purpose oftransferring energy inductively to at least one item, in particular as afunction of activation of the induction unit by the control unit. Theinduction unit is advantageously configured as an induction heating unitand, in at least one operating state, supplies energy in particular toat least one item configured as a cookware item for the purpose ofheating the cookware item, in particular as a function of activation ofthe induction unit by the control unit.

In particular the control unit is provided to control and/or regulate atleast the induction unit. A “control unit” refers in particular to anelectronic unit which, in at least one operating state, controls and/orregulates at least one appliance function and/or at least one appliancemain function, in particular an inductive transfer of energy to at leastone item, advantageously the heating of at least one cookware item. Thecontrol unit in particular has at least one computation unit and, inparticular in addition to the computation unit, at least one storageunit, in which in particular at least one control and/or regulationprogram is stored, which is provided in particular for execution by thecomputation unit. In particular the control unit is provided to controland/or regulate at least one in particular electrical and/or electroniccooktop unit that is different from the control unit. A “cooktop unit”refers in particular to at least one part, in particular a sub-assembly,of a cooktop, in particular of an induction cooktop. At least onecooktop unit could be for example at least one operator interface and/orthe induction unit and/or at least one inverter and/or at least oneextractor unit and/or at least one cooktop electronics unit and/or thesensor unit.

A “sensor unit” refers in particular to a unit which has at least onesensor element configured as a detector to detect at least one sensorparameter and which is provided in particular to output a valuecharacterizing the sensor parameter, the sensor parameter advantageouslybeing a physical and/or chemical variable. For example the sensor unitcould actively detect the sensor parameter in at least one operatingstate, in particular by generating and emitting a measurement signal, inparticular an electrical and/or optical measurement signal.Alternatively or additionally the sensor unit could passively detect thesensor parameter in at least one operating state, in particular bycapturing at least one property change of at least one sensor partand/or of the sensor element. In particular at least a majority andadvantageously each of the sensor elements of the plurality of sensorelements has at least one detector for detecting at least one sensorparameter.

“At least a majority” of a number of elements refers in particular to aportion of at least 70%, in particular at least 80%, advantageously atleast 90% and preferably at least 95% of the number of elements. A“plurality” of items, in particular of sensor elements and/or inductionunits refers in particular to a number of at least six, in particular atleast nine, advantageously at least twelve, particularly advantageouslyat least sixteen, preferably at least twenty-five, particularlypreferably at least thirty-six, preferentially at least forty-nine andparticularly preferentially at least sixty-four items.

The expression that in a mounted position the sensor unit is arranged“above” the induction unit means in particular that in a mountedposition the sensor unit is at a greater distance from a base than theinduction unit in at least one vertical direction and/or in a mountedposition the sensor unit is at a shorter distance from at least onepositioned cookware item and/or the placement plate than the inductionunit in at least one vertical direction. In a mounted position thevertical direction is aligned in particular at least substantiallyparallel to a gravity direction and/or at least substantiallyperpendicular to a main extension plane of the placement plate. The basecould be for example a bottom and/or a floor and/or a placement surface.

“Substantially parallel” here refers in particular to an alignment of adirection relative to a reference direction, in particular in one plane,the direction deviating by in particular maximum 8°, advantageouslymaximum 5° and particularly advantageously maximum 2° from the referencedirection. The expression “substantially perpendicular” here refers inparticular to an alignment of a direction relative to a referencedirection, the direction and the reference direction being at an angleof 90°, in particular when viewed in one plane, and the angle having amaximum deviation of in particular maximum 8°, advantageously maximum 5°and particularly advantageously maximum 2°. A “main extension plane” ofan item refers in particular to a plane that is parallel to a largestside face of a smallest imaginary geometric cuboid that still enclosesthe item completely and runs in particular through the center point ofthe cuboid.

For example in a mounted position the sensor unit could be arranged inparticular on a side of the placement plate facing away from theinduction unit and/or facing the cookware item. In a mounted positionthe sensor unit is advantageously arranged on a side of the placementplate facing the induction unit and/or facing away from the cookwareitem. In a mounted position the sensor unit is arranged between theplacement plate and the induction unit, in particular when viewed in thevertical direction. For example in a mounted position the sensor unitcould be arranged in close proximity above the induction unit and couldin particular be positioned on the induction unit. For example thesensor unit could have at least one substrate, on which the plurality ofsensor elements of the sensor unit could be arranged in at least onemounted state. The substrate could be in the manner of a plate forexample and could be much thinner than a longitudinal extension and/ortransverse extension of the substrate. For example the substrate couldbe formed at least largely of at least one plastic, for examplepolyimide. The substrate could be for example a circuit board and/or afoil. In particular at least one, in particular at least a majority andadvantageously each of the sensor elements, in particular the activitysensor elements and/or the presence sensor elements and/or thetemperature sensor elements, could be arranged in the manner of aconductor path on the substrate. At least one, in particular at least amajority and advantageously each of the sensor elements, in particularthe activity sensor elements and/or the presence sensor elements and/orthe temperature sensor elements, could be made in particular at leastlargely of copper and/or aluminum and/or nickel.

Alternatively or additionally in a mounted position the sensor unitcould be arranged in particular in close proximity to the placementplate and advantageously on the placement plate. For example in amounted position the sensor unit could in particular be fastened to theplacement plate, in particular by means of at least one force-fit and/orform-fit and or advantageously material-fit connection and be embodiedfor example as at least one coating. “At least largely” refers inparticular to a portion, in particular a portion by mass and/or volume,of at least 70%, in particular at least 80%, advantageously at least 90%and preferably at least 95%.

A plurality of items, in particular sensor elements and/or inductionunits, arranged “in a distributed manner” means in particular that whenlooking at a perpendicular projection of the items into one plane atleast a first of the items is at a distance from at least a second ofthe items of maximum 300%, in particular maximum 250%, advantageouslymaximum 200%, particularly advantageously maximum 175%, preferablymaximum 150% and particularly preferably maximum 125% of a maximumextension of a larger of the items in the plane and the first item is ata distance from at least a third of the items of at least 300%, inparticular at least 350%, advantageously at least 400%, particularlyadvantageously at least 450%, preferably at least 500% and particularlypreferably at least 600% of a maximum extension of a larger of the itemsin the plane. In particular when looking at a perpendicular projectionof the items into one plane at least 5, in particular at least 10,advantageously at least 20, particularly advantageously at least 30,preferably at least 50 and particularly preferably at least 60 items arearranged on a surface of 130 times the surface extension of one of theitems in the plane. A “distance” between at least two items here and inthe following refers in particular to an extension from a geometriccenter point and/or center of gravity of one of the items to a geometriccenter point and/or center of gravity of a further item.

A plurality of items, in particular sensor elements and/or inductionunits, arranged “in the manner of a matrix” refers in particular to aplurality of items arranged in a regular manner, advantageously in theform of rows and columns and preferably in the form of a matrix withrows and columns. In particular the rows and columns of the matrixdefine at least two axes of the matrix. The axes of the matrix could bealigned for example obliquely relative to one another. The axes of thematrix are advantageously aligned at least substantially perpendicularto one another. In particular distances between in particular directlyadjacent rows of the matrix and/or between in particular directlyadjacent columns of the matrix could be different. The distances betweenin particular directly adjacent rows of the matrix and/or between inparticular directly adjacent columns of the matrix are advantageously atleast substantially and advantageously exactly identical, whenmanufacturing tolerances are taken into account. The matrix could be amathematical matrix for example and could be described in particular bymeans of matrices. For example a number of columns of the matrix and anumber of lines of the matrix could be different. A number of columns ofthe matrix and a number of lines of the matrix is advantageously atleast substantially and advantageously exactly identical. The matrix ofitems could be for example a 3×3, in particular a 4×4, advantageously a5×5, particularly advantageously a 6×6, preferably a 7×7 andparticularly preferably an 8×8 matrix of items. The matrix canparticularly advantageously be an X×Y matrix, in which at least one ofthe variables X and Y has a value of at least three, in particular atleast four, advantageously at least five, particularly advantageously atleast eight, preferably at least twelve and particularly preferably atleast fifteen.

A “presence sensor element” refers in particular to a sensor elementwhich, in at least one operating state, detects at least a presenceand/or absence of at least one object. In particular the presenceparameter of the object characterizes at least a presence and/or absenceof the object. In particular in addition to a presence and/or absence ofat least one object the presence sensor element could be provided forexample to detect at least a shape and/or at least a configurationand/or at least a size and/or at least a suitability for inductionand/or at least a material of the object. At least one object could befor example flatware and/or kitchenware and/or a token. At least oneobject is advantageously a cookware item, which is arranged, inparticular positioned, above the induction unit and advantageously abovethe placement plate, in particular for heating.

An “activity sensor element” refers in particular to a sensor elementwhich, in at least one operating state, detects at least one activitystate of the induction unit. In particular the activity parameter of theinduction unit characterizes at least one activity state of theinduction unit. For example the activity sensor element could detect inthe form of the activity parameter whether the induction unit is in anactivated state or a deactivated state. Alternatively or additionallythe activity sensor element could detect in the form of the activityparameter for example a degree of activity of the induction unit, whichcould indicate in particular the heating power the induction unitsupplies in the operating state, in particular to heat the cookwareitem. In particular the activity sensor element detects the activityparameter of the induction unit by detecting a voltage induced in theactivity sensor element, which is induced in particular by anelectromagnetic alternating field supplied by the induction unit.

A “temperature sensor element” refers in particular to a sensor elementwhich, in at least one operating state, detects at least one temperatureof at least one unit. In particular the temperature parameter of theunit characterizes at least one temperature of the unit. At least oneunit could be for example the induction unit and/or the placement plateand/or the cookware item and/or at least one item to be cooked in thecookware item.

For example the control unit could be provided to determine a presenceand/or absence of the object in particular as a function of the presenceparameter and advantageously also as a function of the temperatureparameter, in particular in the case of at least one small object. Thisin particular allows particularly precise detection of a presence and/orabsence of the object.

“Provided” means in particular specifically programmed, designed and/orequipped. That an item is provided for a particular function means inparticular that the item fulfils and/or performs said particularfunction in at least one application and/or operating state.

It is further proposed that, when looking at a perpendicular projectionof a placement surface, which is at least defined by the induction unit,onto one plane, the sensor unit extends over a surface portion of atleast 50%, in particular at least 60%, advantageously at least 70%,particularly advantageously at least 80%, preferably at least 90% andparticularly preferably at least 95% of a surface spanned by theplacement surface in the plane. When looking at a perpendicularprojection of a placement surface onto one plane, the sensor unitparticularly advantageously extends over an entire surface extensionspanned by the placement surface in the plane. A “placement surface”refers in particular to a surface portion of the placement plate, whichis provided for the placement of the object, in particular for thepurpose of transferring energy to the object. The placement surface isadvantageously configured as a cooking surface and is provided inparticular for the placement of cookware, in particular for the purposeof heating the cookware. In particular in a mounted position at least amajority and advantageously all of the induction units are arrangedbelow the placement surface. The placement surface is defined inparticular by an arrangement of at least a majority and advantageouslyall of the induction units. When looking at a perpendicular projectionof the placement surface and the induction units onto one plane, asurface spanned by the placement surface in the plane and a surfacespanned by the induction units in the plane are congruent over a surfaceportion of at least 90%, in particular at least 92%, advantageously atleast 95%, particularly advantageously at least 97%, preferably at least99% and particularly preferably completely. This in particular allowsdetection of the sensor parameter over a majority of the placementsurface, providing in particular a high level of operating convenience.

For example at least one, in particular at least a majority andadvantageously each of the activity sensor elements and at least one, inparticular at least a majority and advantageously each of the presencesensor elements could be configured differently from one another.Preferably at least one, in particular at least a majority andadvantageously each of the activity sensor elements and at least one, inparticular at least a majority and advantageously each of the presencesensor elements could be configured as a single piece with one anotherand in particular identically, in particular as one and the sameelement. “As a single piece” here in particular means connected at leastwith a material fit, for example by means of a welding process, anadhesion process, a spraying process and/or another process that appearsexpedient to the person skilled in the art, and/or advantageously formedin one piece, for example by being produced from one casting and/orbeing produced using a single or multiple component spraying method andadvantageously from a single workpiece. This means in particular thatfew different parts and/or little storage capacity is required. Inparticular costs can be kept low, as in particular one sensor elementcan be used to detect at least two different parameters, in particularavoiding additional hardware costs.

It is further proposed that at least one, in particular at least amajority and advantageously each of the activity sensor elements and/orpresence sensor elements respectively has at least one induction coil.In at least one mounted state at least one, in particular at least amajority and advantageously each of the activity sensor elements and/orpresence sensor elements is arranged in particular in a resonantcircuit, which is in particular part of the induction device. Inparticular the induction device has at least one resonant capacitor andin particular at least one electrical resistance, in particular anelectrical cross resistance, in particular per activity sensor elementand/or per presence sensor element, these being arranged in particularin series with the induction coil and advantageously in the resonantcircuit. In the case of presence sensor elements in particular thesensor unit detects the sensor parameter in the form of a presenceparameter in particular by means of a change in a resonant frequency ofthe induction coil and/or by means of a change in a resonant frequencyof the resonant circuit and/or by means of a change in an inductance ofthe induction coil. This in particular allows optimal detection of thesensor parameter in a structurally simple manner, allowing costs to bekept low and/or detection quality to be optimized.

For example at least one, in particular at least a majority andadvantageously each of the activity sensor elements and/or presencesensor elements and at least one, in particular at least a majority andadvantageously each of the temperature sensor elements could beconfigured as a single piece with one another and in particularidentically. A respective temperature sensor element could be configuredfor example as a resistance wire, which is wound in particular into acoil and could in particular define the induction coil of the respectiveactivity sensor element and/or the respective presence sensor element.Preferably at least one, in particular at least a majority andadvantageously each of the activity sensor elements and/or presencesensor elements and at least one, in particular at least a majority andadvantageously each of the temperature sensor elements could beconfigured differently from one another. This in particular allows ahigh level of flexibility, in particular in respect of an arrangement ofthe temperature sensor elements relative to the activity sensor elementsand/or presence sensor elements. It can allow in particular simpleand/or fast and/or economical production.

It is further proposed that at least one, in particular at least amajority and advantageously each of the activity sensor elements and/orpresence sensor elements and at least one, in particular at least amajority and advantageously each of the temperature sensor elements arearranged on different layers of at least one substrate of the sensorunit. In particular at least one, in particular at least a majority andadvantageously each of the activity sensor elements and/or presencesensor elements is arranged on a first layer of the substrate and atleast one, in particular at least a majority and advantageously each ofthe temperature sensor elements is arranged on at least one second layerof the substrate located opposite the first layer of the substrate inrelation to a main extension plane of the substrate. This in particularallows a compact embodiment to be achieved and/or reduces the number ofdifferent parts and/or storage capacity required.

It is also proposed that at least one, in particular at least a majorityand advantageously each of the activity sensor elements and/or presencesensor elements and at least one, in particular at least a majority andadvantageously each of the temperature sensor elements are connectedelectrically in series. In particular one of the activity sensorelements and/or presence sensor elements and one of the temperaturesensor elements respectively are connected electrically in series. Thissimple electrical circuit allows optimal detection, which in particularallows fast and/or simple mounting.

It is further proposed that at least one, in particular at least amajority and advantageously each of the activity sensor elements and/orpresence sensor elements and at least one, in particular at least amajority and advantageously each of the temperature sensor elements areconfigured as a single piece with one another. In particular one of theactivity sensor elements and/or presence sensor elements and at leastone of the temperature sensor elements respectively are configured as asingle piece with one another. At least one, in particular at least amajority and advantageously each of the activity sensor elements and/orpresence sensor elements in particular has at least one electricalconduction element, which is wound in particular into the induction coiland is configured in particular as a thermistor or RTD and forms thetemperature sensor element. This in particular reduces the number ofdifferent parts and/or storage capacity required.

It is further proposed that, when looking at a perpendicular projectionof the sensor unit onto one plane, said plane being aligned inparticular parallel to a main extension plane of the placement plateand/or to a main extension plane of the induction unit, at least one, inparticular at least a majority and advantageously each of the activitysensor elements and/or presence sensor elements and at least one, inparticular at least a majority and advantageously each of thetemperature sensor elements are arranged so that they overlap at leastin sections, in particular at least largely and advantageouslycompletely. The expression that at least two items, in particular atleast one of the activity sensor elements and/or presence sensorelements and at least one of the temperature sensor elements arearranged so that they “overlap at least in sections” when looking at aperpendicular projection of the sensor unit onto one plane means inparticular that, when looking at a perpendicular projection of thesensor unit onto one plane, the items are arranged so that they overlapover a surface portion of at least 30%, in particular at least 50%,advantageously at least 70%, particularly advantageously at least 80%,preferably at least 90% and particularly preferably at least 95% of asurface of one of the smaller items in the plane. This in particularensures identical resolution capacity when detecting the presenceparameter and/or activity parameter and the temperature parameter,resulting in particular in a high level of operating convenience.

For example at least a majority and advantageously all of the activitysensor elements and/or presence sensor elements and/or temperaturesensor elements could be arranged on different substrates and thesubstrates could be arranged so that they overlap one another.Preferably at least a majority and advantageously all of the activitysensor elements and/or presence sensor elements and/or temperaturesensor elements are arranged on the same substrate, thereby inparticular reducing the number of different parts and/or storagecapacity required and/or minimizing hardware costs.

It is also proposed that at least one, in particular at least a majorityand advantageously each of the temperature sensor elements is configuredas a thermistor or RTD. The thermistor is in particular a resistancethermometer and could be configured for example as a high-temperatureconductor and/or a low-temperature conductor. This in particular allowsprecise detection of the temperature parameter, thereby allowing inparticular optimal cooking results and/or a high level of operatingconvenience.

A number of activity sensor elements and/or presence sensor elements anda number of temperature sensor elements could be different from oneanother for example. A number of activity sensor elements and/orpresence sensor elements and a number of temperature sensor elements arepreferably identical. In particular just one temperature sensor elementis assigned in particular to one of the activity sensor elements and/orpresence sensor elements respectively. A number of activity sensorelements and/or presence sensor elements and/or temperature sensorelements is in particular greater and advantageously substantiallygreater than a number of induction units. This allows a high level ofoperating convenience to be achieved and/or simple assignment of adetected temperature parameter to a detected activity parameter and/orto a detected presence parameter.

It is further proposed that, when looking at a perpendicular projectionof the sensor unit onto one plane, at least one, in particular at leasta majority and advantageously each of the activity sensor elementsand/or presence sensor elements and/or temperature sensor elementsrespectively has a surface extension of maximum 25 cm², in particularmaximum 20 cm², advantageously maximum 15 cm², particularlyadvantageously maximum 12 cm², preferably maximum 10 cm², andparticularly preferably maximum 9 cm² in the plane. In particular atleast one, in particular at least a majority and advantageously each ofthe sensor elements, in particular the activity sensor elements and/orpresence sensor elements and/or temperature sensor elements, could be ofa size that could be tailored in particular to an object and/or item tobe detected. This in particular allows a greater spatial resolutioncapacity to be achieved, the smaller the size of the sensor elements,allowing in particular precise detection of small objects and/oroutlines and/or configurations of objects. This in particular allows ahigh resolution capacity to be achieved, thereby allowing in particulareven small and/or minimal sizes to be detected to be detected. In thecase of the presence sensor elements for example in particular a shapeand/or configuration of even very small objects can be detected easily.Compared with sensor elements formed in particular by the inductionunits, in particular a fraction of the energy has to be transferred tothe item to be detected, thereby minimizing and/or completelyeliminating unwanted heating of the item to be detected. In the case ofthe temperature sensor elements for example hazardous situations inparticular can be avoided or at least reduced by the high resolutioncapacity, in particular in the case of an automatic cooking operation.

Particularly advantageous properties in respect of detection of a sensorparameter can be achieved in particular by an induction appliance, inparticular by an induction cooktop, with at least one inventiveinduction device.

The induction device here is not limited to the application andembodiment described above. In particular the induction device can havea different number of individual elements, parts and units from thenumber cited herein to comply with the mode of operation describedherein.

Further advantages will emerge from the description of the drawing thatfollows. The drawing shows exemplary embodiments of the invention. Thedrawing, description and claims contain numerous features incombination. The person skilled in the art will also expedientlyconsider the features individually and combine them in useful furthercombinations.

In the drawing:

FIG. 1 shows a schematic top view of an induction appliance with aninduction device,

FIG. 2 shows a schematic sectional view of a detail of the inductionappliance with the induction device,

FIG. 3 shows a schematic top view of a detail of a sensor unit of theinduction device with a plurality of presence sensor elements andactivity sensor elements,

FIG. 4 shows an enlarged schematic view of one of the presence sensorelements and one of the activity sensor elements from FIG. 3,

FIG. 5 shows a schematic top view of a detail of the sensor unit with aplurality of temperature sensor elements, omitting the electricalconnection of the temperature sensor elements,

FIG. 6 shows an enlarged schematic view of one of the plurality oftemperature sensor elements,

FIG. 7 shows a schematic top view of a detail of the sensor unit withthe presence sensor elements, activity sensor elements and temperaturesensor elements, a substrate of the sensor unit being shown astransparent,

FIG. 8 shows a schematic view of an enlarged detail from FIG. 7,

FIG. 9 shows a schematic view of a resonant circuit of the sensor unit,

FIG. 10 shows a schematic view of a driver circuit of the sensor unit,

FIG. 11 shows a diagram showing a schematic view of normalizedinductance and normalized frequency plotted respectively over anormalized distance between the sensor unit and an object,

FIG. 12 shows a schematic top view of a presence sensor element, anactivity sensor element and a temperature sensor element of a sensorunit of an alternative induction device,

FIG. 13 shows a schematic top view of a presence sensor element, anactivity sensor element and a temperature sensor element of a sensorunit of an alternative induction device.

FIG. 1 shows an induction appliance 30 a in the form of an inductioncooktop, with an induction device 10 a in the form of an inductioncooktop device. In an alternative exemplary embodiment the inductionappliance 30 a and/or the induction device 10 a could be configured forexample to transfer energy inductively to an item (not shown) that isnot a cookware item 38 a. The item could be for example a self-drivingwork implement and/or a hand tool and/or a shutter and/or a remotecontrol unit.

The induction device 10 a has a placement plate 32 a. In the presentexemplary embodiment the placement plate 32 a is in the form of acooktop plate. In a mounted state the placement plate 32 a forms part ofa cooktop outer housing, in particular a cooktop outer housing inparticular of the induction appliance 30 a. The placement plate 32 a isprovided for the placement of cookware 38 a (see FIG. 2).

The induction device 10 a has a plurality of induction units 12 a forheating cookware 38 a (see FIG. 2). Only one of a number of itemspresent is shown with a reference character in each instance in thefigures. The induction units 12 a together define a placement surface 22a. When the induction units 12 a and the placement surface 22 a areprojected in a perpendicular manner into one plane, in the presentexemplary embodiment a surface spanned by the induction units 12 a inthe plane and a surface spanned by the placement surface 22 a in theplane are substantially congruent. Only one of the induction units 12 ais described in the following.

In a mounted position the induction unit 12 a is arranged below theplacement plate 32 a. The induction unit 12 a is provided to heatcookware 38 a positioned on the placement plate 32 a above the inductionunit 12 a. In the present exemplary embodiment the induction unit 12 ais configured as an induction heating unit.

The induction device 10 a has an operator interface 34 a for inputtingand/or selecting operating parameters (see FIG. 1), for example aheating power and/or heating power density and/or a heating zone. Theoperator interface 34 a is provided to output a value of an operatingparameter to an operator.

The induction device 10 a comprises a control unit 16 a. The controlunit 16 a is provided to perform actions and/or change settings as afunction of operating parameters input by means of the operatorinterface 34 a. In an operating state the control unit 16 a regulates anenergy supply to the induction unit 12 a.

The control unit 16 a is provided to analyze and/or process at least onesensor parameter detected by a sensor unit 14 a. The induction device 10a comprises the sensor unit 14 a (see FIGS. 2 to 6). In a mountedposition the sensor unit 14 a is arranged below the placement plate 32 a(see FIG. 2). In a mounted position the sensor unit 14 a is arrangedabove the induction unit 12 a. In a mounted position the sensor unit 14a is arranged between the induction unit 12 a and the placement plate 32a.

When looking at a perpendicular projection of the placement surface 22a, which is defined at least by the induction unit 12 a, onto one plane,the sensor unit 14 a extends over a surface portion of substantially100% of a surface spanned by the placement surface 22 a in the plane.When the sensor unit 14 a and placement surface 22 a are extended in aperpendicular manner into one plane, in the present exemplary embodimenta surface spanned by the sensor unit 14 a in the plane and a surfacespanned by the placement surface 22 a in the plane are substantiallycongruent.

The sensor unit 14 a is provided to detect at least one sensorparameter. In the present exemplary embodiment the sensor unit 14 a isprovided to detect at least three different sensor parameters, inparticular at least three different sorts and/or types of sensorparameter. To detect the three different sorts and/or types of sensorparameter the sensor unit 14 a has three sensor elements 18 a, 24 a, 26a, each being provided to detect one of the different sorts and/or typesof sensor parameter.

The sensor unit 14 a has a substrate 36 a (see FIGS. 2 to 8). The sensorelements 18 a, 24 a, 26 a are arranged on the substrate 36 a. Forexample the sensor elements 18 a, 24 a, 26 a could be printed onto thesubstrate 36 a and/or applied to the substrate 36 a by coating.

The sensor unit 14 a has a plurality of presence sensor elements 18 aarranged in a distributed manner (see FIGS. 3 and 4). In the presentexemplary embodiment the presence sensor elements 18 a are arranged inthe manner of a matrix. A number of presence sensor elements 18 a issubstantially greater than a number of induction units 12 a.

The presence sensor elements 18 a are provided to detect at least onesensor parameter in the form of a presence parameter of at least oneobject 20 a. The object 20 a is part of the induction device 10 a. Inthe present exemplary embodiment at least one object 20 a is thecookware 38 a. The presence sensor elements 18 a are provided to detectat least one sensor parameter in the form of a presence parameter of thecookware 38 a. In the operating state the presence sensor elements 18 adetect at least one sensor parameter in the form of a presence parameterof the object 20 a and/or the cookware 38 a.

Each of the presence sensor elements 18 a has at least one inductioncoil. In the operating state the presence sensor elements 18 a detectthe sensor parameter in the form of a presence parameter of the object20 a and/or the cookware 38 a by means of a change in an impedanceand/or a resonant frequency of the induction coil.

The sensor unit 14 a has a plurality of activity sensor elements 24 aarranged in a distributed manner (see FIGS. 3 and 4). In the presentexemplary embodiment the activity sensor elements 24 a are arranged inthe manner of a matrix. A number of activity sensor elements 24 a issubstantially greater than a number of induction units 12 a.

The activity sensor elements 24 a are provided to detect at least onesensor parameter in the form of an activity parameter of the inductionunit 12 a. In the operating state the activity sensor elements 24 adetect at least one sensor parameter in the form of an activityparameter of the induction unit 12 a. Each of the activity sensorelements 24 a has at least one induction coil.

A number of activity sensor elements 24 a and a number of presencesensor elements 18 a are identical. The activity sensor elements 24 aand the presence sensor elements 18 a are configured as a single piecewith one another. One of the activity sensor elements 24 a and one ofthe presence sensor elements 18 a respectively are configured as asingle piece with one another.

The sensor unit 14 a has a plurality of temperature sensor elements 26 aarranged in a distributed manner (see FIGS. 5 and 6). In the presentexemplary embodiment the temperature sensor elements 26 a are arrangedin the manner of a matrix. A number of temperature sensor elements 26 ais substantially greater than a number of induction units 12 a.

The temperature sensor elements 26 a are provided to detect at least onesensor parameter in the form of a temperature parameter of at least oneunit 28 a. In the operating state the temperature sensor elements 26 adetect at least one sensor parameter in the form of a temperatureparameter of at least one unit 28 a.

The unit 28 a is part of the induction device 10 a. In the presentexemplary embodiment at least one unit 28 a is the placement plate 32 a.The temperature sensor elements 26 a are provided to detect at least onesensor parameter in the form of a temperature parameter of the placementplate 32 a. In the operating state the temperature sensor elements 26 adetect at least one sensor parameter in the form of a temperatureparameter of the unit 28 a and/or the placement plate 32 a. Each of thetemperature sensor elements 26 a is configured as an RTD. In theoperating state the temperature sensor elements 26 detect the sensorparameter in the form of a temperature parameter of the unit 28 a and/orthe placement plate 32 a by means of a change in an electricalresistance of the respective temperature sensor element 26 a as afunction of a temperature.

A number of activity sensor elements 24 a and a number of temperaturesensor elements 26 a are identical. A number of presence sensor elements18 a and a number of temperature sensor elements 26 a are identical.

One of the presence sensor elements 18 a and one of the temperaturesensor elements 26 a respectively are configured differently from oneanother. One of the activity sensor elements 24 a and one of thetemperature sensor elements 26 a respectively are configured differentlyfrom one another. Each of the presence sensor elements 18 a and each ofthe temperature sensor elements 26 a are configured differently from oneanother. Each of the activity sensor elements 24 a and each of thetemperature sensor elements 26 a are configured differently from oneanother.

In the present exemplary embodiment one of the presence sensor elements18 a and one of the temperature sensor elements 26 a respectively arearranged on different layers of the substrate 36 a of the sensor unit 14a. One of the activity sensor elements 24 a and one of the temperaturesensor elements 26 a respectively are arranged on different layers ofthe substrate 36 a of the sensor unit 14 a. Each of the presence sensorelements 18 a and each of the temperature sensor elements 26 a arearranged on different layers of the substrate 36 a of the sensor unit 14a. Each of the activity sensor elements 24 a and each of the temperaturesensor elements 26 a are arranged on different layers of the substrate36 a of the sensor unit 14 a.

When looking at a perpendicular projection of the sensor unit 14 a ontoone plane, one of the activity sensor elements 24 a and one of thetemperature sensor elements 26 a respectively are arranged so that theyoverlap in sections and advantageously completely (see FIGS. 7 and 8).When looking at a perpendicular projection of the sensor unit 14 a ontoone plane, one of the presence sensor elements 18 a and one of thetemperature sensor elements 26 a respectively are arranged so that theyoverlap in sections and advantageously completely.

In the present exemplary embodiment, when looking at a perpendicularprojection of the sensor unit 14 a onto one plane, each of the presencesensor elements 18 a has a surface extension of substantially 9 cm² inthe plane. When looking at a perpendicular projection of the sensor unit12 a onto one plane, each of the presence sensor elements 18 a has asurface extension of substantially 3×3 cm² in the plane.

In the present exemplary embodiment, when looking at a perpendicularprojection of the sensor unit 14 a onto one plane, each of the activitysensor elements 24 a has a surface extension of substantially 9 cm² inthe plane. When looking at a perpendicular projection of the sensor unit12 a onto one plane, each of the activity sensor elements 24 a has asurface extension of substantially 3×3 cm² in the plane.

In the present exemplary embodiment, when looking at a perpendicularprojection of the sensor unit 14 a onto one plane, each of thetemperature sensor elements 26 a has a surface extension ofsubstantially 9 cm² in the plane. When looking at a perpendicularprojection of the sensor unit 12 a onto one plane, each of thetemperature sensor elements 26 a has a surface extension ofsubstantially 3×3 cm² in the plane.

The sensor unit 14 a has a plurality of electrical resonant circuits 50a (see FIG. 9). In the present exemplary embodiment the sensor unit 14 ahas one electrical resonant circuit 50 a per presence sensor element 18a. Only the illustrated resonant circuit 50 a is described in thefollowing.

The sensor unit 14 a in particular has one resonant capacitance 54 a perresonant circuit 50 a. The resonant capacitance 54 a and the presencesensor element 18 a, in particular the induction coil of the presencesensor element 18 a, are connected electrically in series. In thepresent exemplary embodiment the resonant capacitance 54 a is configuredas a capacitor.

The sensor unit 14 a has one oscillator 52 a, in particular per resonantcircuit 50 a. In the present exemplary embodiment the oscillator 52 acomprises a Clapp oscillator.

One of the presence sensor elements 18 a, the resonant capacitance 54 aand the oscillator 52 a are part of the resonant circuit 50 a. When anobject 20 a approaches the presence sensor element 18 a, the presencesensor element 18 a detects the object 20 a, in particular by means of achange, advantageously by means of an increase, in an inductance of theinduction coil.

The sensor unit 14 a has a plurality of electrical driver circuits 56 a(see FIG. 10). In the present exemplary embodiment the sensor unit 14 ahas one electrical driver circuit 56 a per presence sensor element 18 a.Only the illustrated driver circuit 56 a is described in the following.

The sensor unit 14 a has one electrical resistance 58 a, in particularper driver circuit 56 a. The electrical resistance 58 a and the presencesensor element 18 a, in particular the induction coil of the presencesensor element 18 a, are connected electrically in series. In thepresent exemplary embodiment the electrical resistance 58 a isconfigured as an electrical cross resistance.

The sensor unit 14 a has one energy source 60 a, in particular perdriver circuit 56 a. The energy source 60 a is provided to supplyelectrical energy for the presence sensor element 18 a. In the operatingstate the control unit 16 a operates the presence sensor element 18 a,in particular by means of the energy source 60 a, at a fixed frequency.In the operating state the control unit 16 a detects an impedance of thepresence sensor element 18 a.

When an object 20 a approaches the presence sensor element 18 a, thepresence sensor element 18 a detects the object 20 a in particular bymeans of a change, advantageously by means of an increase, in aninductance of the induction coil.

In the operating state the control unit 16 a detects an electric voltageat a first measurement point 62 a, which is located on a side of thepresence sensor element 18 a facing the resistance 58 a. In theoperating state the control unit 16 a detects an electric voltage at asecond measurement point 64 a, which is located on a side of thepresence sensor element 18 a facing away from the resistance 58 a. Inthe operating state the control unit 16 a calculates an impedance of thepresence sensor element 18 a from the detected electric voltages andfrom the electrical resistance 58 a.

It is assumed in the following that the electric voltage at the firstmeasurement point 62 a is V1 and the electric voltage at the secondmeasurement point 64 a is V2 and Rs is the electrical resistance 58 a.In the operating state the control unit 16 a determines an impedance Zof the presence sensor element 18 a using the following formula:

Z=Rs(V2−V1)/V1  1.

FIG. 11 shows a diagram, in which a normalized inductance of one of theinduction coils and a normalized frequency are plotted respectively overa normalized distance between the sensor unit 14 a and the object 20 a.On a first y-axis 40 a an inductance of one of the induction coils isplotted relative to an inductance of the induction coil in the absenceof the object 20 a. On a second y-axis 42 a a frequency of one of theinduction coils is plotted relative to a frequency of the induction coilin the absence of the object 20 a. On an x-axis 44 a a distance betweenthe sensor unit 14 a and the object 20 a is plotted relative to amaximum extension of one of the sensor elements 18 a, 24 a, 26 a. In thepresent exemplary embodiment the maximum extension of one of the sensorelements 18 a, 24 a, 26 a is substantially 3 cm.

A continuous progression curve 48 a shows a progression of thenormalized inductance of one of the induction coils. A brokenprogression curve 46 a shows a progression of the normalized frequencyof one of the induction coils.

It can be seen from FIG. 11 that the nearer the object 20 a comes to thesensor unit 14 a, the smaller the inductance of the induction coil. Forexample in the case of a normalized distance of 0.1, which in thepresent exemplary embodiment corresponds in particular to a distance ofsubstantially 3 mm between the object 20 a and the sensor unit 14 a, theinductance of the induction coil has a value of approximately 50% of thevalue of the inductance of the induction coil when the object 20 a issubstantially 30 mm away from the sensor unit 14 a.

It can be seen from FIG. 11 that the nearer the object 20 a comes to thesensor unit 14 a, the higher the frequency of the induction coil, inparticular due to the decreasing inductance of the induction coil.

FIGS. 12 and 13 show further exemplary embodiments of the invention. Thedescriptions that follow are essentially limited to the differencesbetween the exemplary embodiments, it being possible to refer to thedescription of the exemplary embodiment in FIGS. 1 to 11 for parts,features and functions that remain the same. To distinguish between theexemplary embodiments, the letter a in the reference characters of theexemplary embodiment in FIGS. 1 to 11 is replaced by the letters b and cin the reference characters of the exemplary embodiment in FIGS. 12 and13. It is possible in principle also to refer to the drawings and/ordescription of the exemplary embodiment in FIGS. 1 to 11 for parts withthe same designation, in particular for parts with the same referencecharacters.

FIG. 12 shows a detail of a sensor unit 14 b of an alternative inductiondevice 10 b. The sensor unit 14 b has a plurality of presence sensorelements 18 b, a plurality of activity sensor elements 24 b and aplurality of temperature sensor elements 26 a, only one of each of whichis shown. One of the presence sensor elements 18 b and one of theactivity sensor elements 24 b respectively are configured as a singlepiece with one another.

One of the presence sensor elements 18 b and one of the temperaturesensor elements 26 b respectively are configured differently from oneanother. One of the activity sensor elements 24 b and one of thetemperature sensor elements 26 b respectively are configured differentlyfrom one another. Each of the presence sensor elements 18 b and each ofthe temperature sensor elements 26 b are configured differently from oneanother. Each of the activity sensor elements 24 b and each of thetemperature sensor elements 26 b are configured differently from oneanother.

In the present exemplary embodiment one of the presence sensor elements18 b and one of the temperature sensor elements 26 b respectively areconnected electrically in series. One of the activity sensor elements 24b and one of the temperature sensor elements 26 b respectively areconnected electrically in series.

FIG. 13 shows a detail of a sensor unit 14 c of an alternative inductiondevice 10 c. The sensor unit 14 c has a plurality of presence sensorelements 18 c, a plurality of activity sensor elements 24 c and aplurality of temperature sensor elements 26 c, only one of each of whichis shown. One of the presence sensor elements 18 c and one of theactivity sensor elements 24 c respectively are configured as a singlepiece with one another. One of the presence sensor elements 18 c and oneof the temperature sensor elements 26 c respectively are configured as asingle piece with one another. One of the activity sensor elements 24 cand one of the temperature sensor elements 26 c respectively areconfigured as a single piece with one another.

REFERENCE CHARACTERS

-   10 Induction device-   12 Induction unit-   14 Sensor unit-   16 Control unit-   18 Presence sensor element-   20 Object-   22 Placement surface-   24 Activity sensor element-   26 Temperature sensor element-   28 Unit-   30 Induction appliance-   32 Placement plate-   34 Operator interface-   36 Substrate-   38 Cookware-   40 First y-axis-   42 Second y-axis-   44 x-axis-   46 Progression curve-   48 Progression curve-   50 Resonant circuit-   52 Oscillator-   54 Resonant capacitance-   56 Driver circuit-   58 Resistance-   60 Energy source-   62 First measurement point-   64 Second measurement point

1-14. (canceled)
 15. An induction device, comprising: an induction unitincluding a sensor unit which is arranged above the induction unit in amounted position and includes a plurality of temperature sensor elementsarranged in a distributed manner and configured to detect a sensorparameter in the form of a temperature parameter of a unit; and acontrol unit configured to analyze the sensor parameter.
 16. Theinduction device of claim 15, constructed in the form of an inductioncooktop device.
 17. The induction device of claim 15, wherein, whenlooking at a perpendicular projection of a placement surface, which isat least defined by the induction unit, onto one plane, the sensor unitextends over a surface portion of at least 50% of a surface spanned bythe placement surface in the plane.
 18. The induction device of claim15, wherein the sensor unit includes a plurality of activity sensorelements arranged in a distributed manner and configured to detect asensor parameter in the form of an activity parameter of the inductionunit.
 19. The induction device of claim 18, wherein at least one of theactivity sensor elements includes an induction coil.
 20. The inductiondevice of claim 15, wherein the sensor unit includes a plurality ofpresence sensor elements arranged in a distributed manner and configuredto detect a sensor parameter in the form of a presence parameter of anobject.
 21. The induction device of claim 20, wherein at least one ofthe activity sensor elements and at least one of the presence sensorelements are configured as a single piece with one another.
 22. Theinduction device of claim 20, wherein at least one of the presencesensor elements and at least one of the temperature sensor elements arearranged on different layers of a substrate of the sensor unit.
 23. Theinduction device of claim 20, wherein at least one of the presencesensor elements and at least one of the temperature sensor elements areconnected electrically in series.
 24. The induction device of claim 20,wherein at least one of the presence sensor elements and at least one ofthe temperature sensor elements are configured as a single piece withone another.
 25. The induction device of claim 20, wherein, when lookingat a perpendicular projection of the sensor unit onto one plane, atleast one of the presence sensor elements and at least one of thetemperature sensor elements are arranged so that they overlap at leastin one section.
 26. The induction device of claim 20, wherein a numberof presence sensor elements and a number of temperature sensor elementsare identical.
 27. The induction device of claim 15, wherein at leastone of the temperature sensor elements is configured as a thermistor orRTD.
 28. The induction device of claim 15, wherein, when looking at aperpendicular projection of the sensor unit onto one plane, at least oneof the temperature sensor elements has a surface extension of maximum 25cm² in the plane.
 29. An induction appliance, comprising an inductiondevice, said induction device comprising an induction unit including asensor unit which is arranged above the induction unit in a mountedposition and includes a plurality of temperature sensor elementsarranged in a distributed manner and configured to detect a sensorparameter in the form of a temperature parameter of a unit, and acontrol unit configured to analyze the sensor parameter.
 30. Theinduction appliance of claim 29, constructed in the form of an inductioncooktop